Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
#define _FILE_OFFSET_BITS 64

#include <sys/types.h>
#include <byteswap.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/list.h>
#include <linux/kernel.h>

#include "util.h"
#include "header.h"
#include "../perf.h"
#include "trace-event.h"
#include "session.h"
#include "symbol.h"
#include "debug.h"

/*
 * Create new perf.data header attribute:
 */
struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
{
	struct perf_header_attr *self = malloc(sizeof(*self));

	if (self != NULL) {
		self->attr = *attr;
		self->ids  = 0;
		self->size = 1;
		self->id   = malloc(sizeof(u64));
		if (self->id == NULL) {
			free(self);
			self = NULL;
		}
	}

	return self;
}

void perf_header_attr__delete(struct perf_header_attr *self)
{
	free(self->id);
	free(self);
}

int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
{
	int pos = self->ids;

	self->ids++;
	if (self->ids > self->size) {
		int nsize = self->size * 2;
		u64 *nid = realloc(self->id, nsize * sizeof(u64));

		if (nid == NULL)
			return -1;

		self->size = nsize;
		self->id = nid;
	}
	self->id[pos] = id;
	return 0;
}

int perf_header__init(struct perf_header *self)
{
	self->size = 1;
	self->attr = malloc(sizeof(void *));
	return self->attr == NULL ? -ENOMEM : 0;
}

void perf_header__exit(struct perf_header *self)
{
	int i;
	for (i = 0; i < self->attrs; ++i)
                perf_header_attr__delete(self->attr[i]);
	free(self->attr);
}

int perf_header__add_attr(struct perf_header *self,
			  struct perf_header_attr *attr)
{
	if (self->frozen)
		return -1;

	if (self->attrs == self->size) {
		int nsize = self->size * 2;
		struct perf_header_attr **nattr;

		nattr = realloc(self->attr, nsize * sizeof(void *));
		if (nattr == NULL)
			return -1;

		self->size = nsize;
		self->attr = nattr;
	}

	self->attr[self->attrs++] = attr;
	return 0;
}

#define MAX_EVENT_NAME 64

struct perf_trace_event_type {
	u64	event_id;
	char	name[MAX_EVENT_NAME];
};

static int event_count;
static struct perf_trace_event_type *events;

int perf_header__push_event(u64 id, const char *name)
{
	if (strlen(name) > MAX_EVENT_NAME)
		pr_warning("Event %s will be truncated\n", name);

	if (!events) {
		events = malloc(sizeof(struct perf_trace_event_type));
		if (events == NULL)
			return -ENOMEM;
	} else {
		struct perf_trace_event_type *nevents;

		nevents = realloc(events, (event_count + 1) * sizeof(*events));
		if (nevents == NULL)
			return -ENOMEM;
		events = nevents;
	}
	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
	events[event_count].event_id = id;
	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
	event_count++;
	return 0;
}

char *perf_header__find_event(u64 id)
{
	int i;
	for (i = 0 ; i < event_count; i++) {
		if (events[i].event_id == id)
			return events[i].name;
	}
	return NULL;
}

static const char *__perf_magic = "PERFFILE";

#define PERF_MAGIC	(*(u64 *)__perf_magic)

struct perf_file_attr {
	struct perf_event_attr	attr;
	struct perf_file_section	ids;
};

void perf_header__set_feat(struct perf_header *self, int feat)
{
	set_bit(feat, self->adds_features);
}

bool perf_header__has_feat(const struct perf_header *self, int feat)
{
	return test_bit(feat, self->adds_features);
}

static int do_write(int fd, const void *buf, size_t size)
{
	while (size) {
		int ret = write(fd, buf, size);

		if (ret < 0)
			return -errno;

		size -= ret;
		buf += ret;
	}

	return 0;
}

#define NAME_ALIGN 64

static int write_padded(int fd, const void *bf, size_t count,
			size_t count_aligned)
{
	static const char zero_buf[NAME_ALIGN];
	int err = do_write(fd, bf, count);

	if (!err)
		err = do_write(fd, zero_buf, count_aligned - count);

	return err;
}

#define dsos__for_each_with_build_id(pos, head)	\
	list_for_each_entry(pos, head, node)	\
		if (!pos->has_build_id)		\
			continue;		\
		else

static int __dsos__write_buildid_table(struct list_head *head, u16 misc, int fd)
{
	struct dso *pos;

	dsos__for_each_with_build_id(pos, head) {
		int err;
		struct build_id_event b;
		size_t len;

		if (!pos->hit)
			continue;
		len = pos->long_name_len + 1;
		len = ALIGN(len, NAME_ALIGN);
		memset(&b, 0, sizeof(b));
		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
		b.header.misc = misc;
		b.header.size = sizeof(b) + len;
		err = do_write(fd, &b, sizeof(b));
		if (err < 0)
			return err;
		err = write_padded(fd, pos->long_name,
				   pos->long_name_len + 1, len);
		if (err < 0)
			return err;
	}

	return 0;
}

static int dsos__write_buildid_table(int fd)
{
	int err = __dsos__write_buildid_table(&dsos__kernel,
					      PERF_RECORD_MISC_KERNEL, fd);
	if (err == 0)
		err = __dsos__write_buildid_table(&dsos__user,
						  PERF_RECORD_MISC_USER, fd);
	return err;
}

int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
			  const char *name, bool is_kallsyms)
{
	const size_t size = PATH_MAX;
	char *filename = malloc(size),
	     *linkname = malloc(size), *targetname;
	int len, err = -1;

	if (filename == NULL || linkname == NULL)
		goto out_free;

	len = snprintf(filename, size, "%s%s%s",
		       debugdir, is_kallsyms ? "/" : "", name);
	if (mkdir_p(filename, 0755))
		goto out_free;

	snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);

	if (access(filename, F_OK)) {
		if (is_kallsyms) {
			 if (copyfile("/proc/kallsyms", filename))
				goto out_free;
		} else if (link(name, filename) && copyfile(name, filename))
			goto out_free;
	}

	len = snprintf(linkname, size, "%s/.build-id/%.2s",
		       debugdir, sbuild_id);

	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
		goto out_free;

	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
	targetname = filename + strlen(debugdir) - 5;
	memcpy(targetname, "../..", 5);

	if (symlink(targetname, linkname) == 0)
		err = 0;
out_free:
	free(filename);
	free(linkname);
	return err;
}

static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
				 const char *name, const char *debugdir,
				 bool is_kallsyms)
{
	char sbuild_id[BUILD_ID_SIZE * 2 + 1];

	build_id__sprintf(build_id, build_id_size, sbuild_id);

	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
}

int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
{
	const size_t size = PATH_MAX;
	char *filename = malloc(size),
	     *linkname = malloc(size);
	int err = -1;

	if (filename == NULL || linkname == NULL)
		goto out_free;

	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, sbuild_id + 2);

	if (access(linkname, F_OK))
		goto out_free;

	if (readlink(linkname, filename, size) < 0)
		goto out_free;

	if (unlink(linkname))
		goto out_free;

	/*
	 * Since the link is relative, we must make it absolute:
	 */
	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, filename);

	if (unlink(linkname))
		goto out_free;

	err = 0;
out_free:
	free(filename);
	free(linkname);
	return err;
}

static int dso__cache_build_id(struct dso *self, const char *debugdir)
{
	bool is_kallsyms = self->kernel && self->long_name[0] != '/';

	return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
				     self->long_name, debugdir, is_kallsyms);
}

static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
{
	struct dso *pos;
	int err = 0;

	dsos__for_each_with_build_id(pos, head)
		if (dso__cache_build_id(pos, debugdir))
			err = -1;

	return err;
}

static int dsos__cache_build_ids(void)
{
	int err_kernel, err_user;
	char debugdir[PATH_MAX];

	snprintf(debugdir, sizeof(debugdir), "%s/%s", getenv("HOME"),
		 DEBUG_CACHE_DIR);

	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
		return -1;

	err_kernel = __dsos__cache_build_ids(&dsos__kernel, debugdir);
	err_user   = __dsos__cache_build_ids(&dsos__user, debugdir);
	return err_kernel || err_user ? -1 : 0;
}

static int perf_header__adds_write(struct perf_header *self, int fd)
{
	int nr_sections;
	struct perf_file_section *feat_sec;
	int sec_size;
	u64 sec_start;
	int idx = 0, err;

	if (dsos__read_build_ids(true))
		perf_header__set_feat(self, HEADER_BUILD_ID);

	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
	if (!nr_sections)
		return 0;

	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
	if (feat_sec == NULL)
		return -ENOMEM;

	sec_size = sizeof(*feat_sec) * nr_sections;

	sec_start = self->data_offset + self->data_size;
	lseek(fd, sec_start + sec_size, SEEK_SET);

	if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
		struct perf_file_section *trace_sec;

		trace_sec = &feat_sec[idx++];

		/* Write trace info */
		trace_sec->offset = lseek(fd, 0, SEEK_CUR);
		read_tracing_data(fd, attrs, nr_counters);
		trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
	}


	if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
		struct perf_file_section *buildid_sec;

		buildid_sec = &feat_sec[idx++];

		/* Write build-ids */
		buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
		err = dsos__write_buildid_table(fd);
		if (err < 0) {
			pr_debug("failed to write buildid table\n");
			goto out_free;
		}
		buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
					  buildid_sec->offset;
		dsos__cache_build_ids();
	}

	lseek(fd, sec_start, SEEK_SET);
	err = do_write(fd, feat_sec, sec_size);
	if (err < 0)
		pr_debug("failed to write feature section\n");
out_free:
	free(feat_sec);
	return err;
}

int perf_header__write(struct perf_header *self, int fd, bool at_exit)
{
	struct perf_file_header f_header;
	struct perf_file_attr   f_attr;
	struct perf_header_attr	*attr;
	int i, err;

	lseek(fd, sizeof(f_header), SEEK_SET);


	for (i = 0; i < self->attrs; i++) {
		attr = self->attr[i];

		attr->id_offset = lseek(fd, 0, SEEK_CUR);
		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
		if (err < 0) {
			pr_debug("failed to write perf header\n");
			return err;
		}
	}


	self->attr_offset = lseek(fd, 0, SEEK_CUR);

	for (i = 0; i < self->attrs; i++) {
		attr = self->attr[i];

		f_attr = (struct perf_file_attr){
			.attr = attr->attr,
			.ids  = {
				.offset = attr->id_offset,
				.size   = attr->ids * sizeof(u64),
			}
		};
		err = do_write(fd, &f_attr, sizeof(f_attr));
		if (err < 0) {
			pr_debug("failed to write perf header attribute\n");
			return err;
		}
	}

	self->event_offset = lseek(fd, 0, SEEK_CUR);
	self->event_size = event_count * sizeof(struct perf_trace_event_type);
	if (events) {
		err = do_write(fd, events, self->event_size);
		if (err < 0) {
			pr_debug("failed to write perf header events\n");
			return err;
		}
	}

	self->data_offset = lseek(fd, 0, SEEK_CUR);

	if (at_exit) {
		err = perf_header__adds_write(self, fd);
		if (err < 0)
			return err;
	}

	f_header = (struct perf_file_header){
		.magic	   = PERF_MAGIC,
		.size	   = sizeof(f_header),
		.attr_size = sizeof(f_attr),
		.attrs = {
			.offset = self->attr_offset,
			.size   = self->attrs * sizeof(f_attr),
		},
		.data = {
			.offset = self->data_offset,
			.size	= self->data_size,
		},
		.event_types = {
			.offset = self->event_offset,
			.size	= self->event_size,
		},
	};

	memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));

	lseek(fd, 0, SEEK_SET);
	err = do_write(fd, &f_header, sizeof(f_header));
	if (err < 0) {
		pr_debug("failed to write perf header\n");
		return err;
	}
	lseek(fd, self->data_offset + self->data_size, SEEK_SET);

	self->frozen = 1;
	return 0;
}

static int do_read(int fd, void *buf, size_t size)
{
	while (size) {
		int ret = read(fd, buf, size);

		if (ret <= 0)
			return -1;

		size -= ret;
		buf += ret;
	}

	return 0;
}

static int perf_header__getbuffer64(struct perf_header *self,
				    int fd, void *buf, size_t size)
{
	if (do_read(fd, buf, size))
		return -1;

	if (self->needs_swap)
		mem_bswap_64(buf, size);

	return 0;
}

int perf_header__process_sections(struct perf_header *self, int fd,
				  int (*process)(struct perf_file_section *self,
						 struct perf_header *ph,
						 int feat, int fd))
{
	struct perf_file_section *feat_sec;
	int nr_sections;
	int sec_size;
	int idx = 0;
	int err = -1, feat = 1;

	nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
	if (!nr_sections)
		return 0;

	feat_sec = calloc(sizeof(*feat_sec), nr_sections);
	if (!feat_sec)
		return -1;

	sec_size = sizeof(*feat_sec) * nr_sections;

	lseek(fd, self->data_offset + self->data_size, SEEK_SET);

	if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
		goto out_free;

	err = 0;
	while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
		if (perf_header__has_feat(self, feat)) {
			struct perf_file_section *sec = &feat_sec[idx++];

			err = process(sec, self, feat, fd);
			if (err < 0)
				break;
		}
		++feat;
	}
out_free:
	free(feat_sec);
	return err;
}

int perf_file_header__read(struct perf_file_header *self,
			   struct perf_header *ph, int fd)
{
	lseek(fd, 0, SEEK_SET);

	if (do_read(fd, self, sizeof(*self)) ||
	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
		return -1;

	if (self->attr_size != sizeof(struct perf_file_attr)) {
		u64 attr_size = bswap_64(self->attr_size);

		if (attr_size != sizeof(struct perf_file_attr))
			return -1;

		mem_bswap_64(self, offsetof(struct perf_file_header,
					    adds_features));
		ph->needs_swap = true;
	}

	if (self->size != sizeof(*self)) {
		/* Support the previous format */
		if (self->size == offsetof(typeof(*self), adds_features))
			bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
		else
			return -1;
	}

	memcpy(&ph->adds_features, &self->adds_features,
	       sizeof(ph->adds_features));
	/*
	 * FIXME: hack that assumes that if we need swap the perf.data file
	 * may be coming from an arch with a different word-size, ergo different
	 * DEFINE_BITMAP format, investigate more later, but for now its mostly
	 * safe to assume that we have a build-id section. Trace files probably
	 * have several other issues in this realm anyway...
	 */
	if (ph->needs_swap) {
		memset(&ph->adds_features, 0, sizeof(ph->adds_features));
		perf_header__set_feat(ph, HEADER_BUILD_ID);
	}

	ph->event_offset = self->event_types.offset;
	ph->event_size   = self->event_types.size;
	ph->data_offset  = self->data.offset;
	ph->data_size	 = self->data.size;
	return 0;
}

static int perf_file_section__process(struct perf_file_section *self,
				      struct perf_header *ph,
				      int feat, int fd)
{
	if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
		pr_debug("Failed to lseek to %Ld offset for feature %d, "
			 "continuing...\n", self->offset, feat);
		return 0;
	}

	switch (feat) {
	case HEADER_TRACE_INFO:
		trace_report(fd);
		break;

	case HEADER_BUILD_ID:
		if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
			pr_debug("Failed to read buildids, continuing...\n");
		break;
	default:
		pr_debug("unknown feature %d, continuing...\n", feat);
	}

	return 0;
}

int perf_header__read(struct perf_header *self, int fd)
{
	struct perf_file_header	f_header;
	struct perf_file_attr	f_attr;
	u64			f_id;
	int nr_attrs, nr_ids, i, j;

	if (perf_file_header__read(&f_header, self, fd) < 0) {
		pr_debug("incompatible file format\n");
		return -EINVAL;
	}

	nr_attrs = f_header.attrs.size / sizeof(f_attr);
	lseek(fd, f_header.attrs.offset, SEEK_SET);

	for (i = 0; i < nr_attrs; i++) {
		struct perf_header_attr *attr;
		off_t tmp;

		if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
			goto out_errno;

		tmp = lseek(fd, 0, SEEK_CUR);

		attr = perf_header_attr__new(&f_attr.attr);
		if (attr == NULL)
			 return -ENOMEM;

		nr_ids = f_attr.ids.size / sizeof(u64);
		lseek(fd, f_attr.ids.offset, SEEK_SET);

		for (j = 0; j < nr_ids; j++) {
			if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
				goto out_errno;

			if (perf_header_attr__add_id(attr, f_id) < 0) {
				perf_header_attr__delete(attr);
				return -ENOMEM;
			}
		}
		if (perf_header__add_attr(self, attr) < 0) {
			perf_header_attr__delete(attr);
			return -ENOMEM;
		}

		lseek(fd, tmp, SEEK_SET);
	}

	if (f_header.event_types.size) {
		lseek(fd, f_header.event_types.offset, SEEK_SET);
		events = malloc(f_header.event_types.size);
		if (events == NULL)
			return -ENOMEM;
		if (perf_header__getbuffer64(self, fd, events,
					     f_header.event_types.size))
			goto out_errno;
		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
	}

	perf_header__process_sections(self, fd, perf_file_section__process);

	lseek(fd, self->data_offset, SEEK_SET);

	self->frozen = 1;
	return 0;
out_errno:
	return -errno;
}

u64 perf_header__sample_type(struct perf_header *header)
{
	u64 type = 0;
	int i;

	for (i = 0; i < header->attrs; i++) {
		struct perf_header_attr *attr = header->attr[i];

		if (!type)
			type = attr->attr.sample_type;
		else if (type != attr->attr.sample_type)
			die("non matching sample_type");
	}

	return type;
}

struct perf_event_attr *
perf_header__find_attr(u64 id, struct perf_header *header)
{
	int i;

	for (i = 0; i < header->attrs; i++) {
		struct perf_header_attr *attr = header->attr[i];
		int j;

		for (j = 0; j < attr->ids; j++) {
			if (attr->id[j] == id)
				return &attr->attr;
		}
	}

	return NULL;
}